Convert JSON arrays to CSV. Handles nested objects (dot-notation flattening), arrays of arrays, missing keys, and multi-level nesting. Choose delimiter, quote style, and whether to include headers. Live preview with row count.
Paste a JSON array (array of objects, array of arrays, or a single object) into the input. Set delimiter (comma, tab, semicolon), whether to include a header row, and how to handle nested objects — either flatten to dot-notation (user.address.city) or stringify them.
The CSV appears in the output panel. A row count is shown. Check that nested fields have flattened correctly and that multi-value arrays are represented as expected.
Click Copy to clipboard or Download CSV. The output is UTF-8 encoded with a BOM for Excel compatibility on Windows. Quote characters are properly escaped.
Array of objects: [{name:"Alice",age:30}] — standard, headers from keys. Array of arrays: [["Alice",30],["Bob",25]] — no headers by default. Single object: {"a":1,"b":2} — converts to a two-row CSV (key, value). Nested objects: {user:{name:"Alice",address:{city:"London"}}} — flattened to user.name, user.address.city columns.
Dot-notation flattening: {address:{city:"London",postcode:"E1"}} becomes two columns — address.city and address.postcode. This is the most useful option for databases and spreadsheets. Stringify: nested objects are JSON.stringify-d and placed in a single cell — useful when you want to preserve the original structure. Arrays in objects are handled as comma-joined strings or separate rows depending on your setting.
If different records have different keys, all unique keys across all records are used as column headers. Missing values for a given record output as empty cells. Example: record 1 has {name, email}, record 2 has {name, phone} — output has three columns: name, email, phone, with record 1 missing phone and record 2 missing email.
A UTF-8 BOM (Byte Order Mark, the sequence EF BB BF at the start of the file) helps Microsoft Excel on Windows correctly detect that the file is UTF-8 encoded. Without it, Excel may interpret the file as Windows-1252, causing accented characters, Chinese text, and other non-ASCII content to display as garbled characters. The BOM is harmless for other applications that handle UTF-8 correctly.
Use the CSV to Excel converter after converting JSON to CSV — this two-step process gives you an Excel file. Alternatively, tools like SheetJS support direct JSON to Excel conversion in JavaScript. For Python: import pandas as pd; df = pd.DataFrame(data); df.to_excel("output.xlsx", index=False).
Arrays within objects (e.g., tags: ["python", "javascript"]) can be handled in three ways: join as string ("python,javascript"), create separate columns for each index (tags.0, tags.1), or create separate rows for each array element. This tool joins arrays as semicolon-separated strings by default, which is the most spreadsheet-compatible approach.
